This invention relates to an elastic pipe clamp, preferably of a moldable and flexible plastic material, having a lower yoke, means for anchoring the clamp to a fixed structure and an upper yoke pivotally joined to the lower yoke by a hinge band. The two yokes are connectable at their free ends by at least two mutually opposed and mutually engagable hooks to hold the pipe in the clamp in a positive manner.
Plastic pipe clamps of this general type in which one side of the upper yoke is integrally hinged to one side of the lower yoke are known as shown, for example, in published German Patent Application No. 24 46 133. In FIG. 3 of that application there is shown such a clamp in which the free ends of the yokes are lockable together and in which the upper yoke has a beak curving out and over the hinge connection between the yokes with a corresponding recess for the beak in the lower yoke. According to the teachings of the patent, the hook rests against the underside of the hinge band when the yokes are in locked position. This hook is supposed to provide additional locking on the hinged side of the clamp to prevent the clamp from prematurely snapping open on that side in case the hinge band either breaks or tears due to deterioration of the material from which the clamp is made.
In use, however, this kind of hinge-band locking has not proved entirely satisfactory. Because the clamp must be ejected from a mold during its manufacture, the inside walls of the recess must have straight, parallel sides and as a consequence the beak cannot be held in place by the side walls of the recess. If for instance the hinge band were to unexpectedly break, it will no longer hold the beak in place and the beak, being more or less flexible, will then bend toward the curved inside wall nearest the center of the clamp and easily slip out of the recess.